虽然在过去的45年中有数十名研究者对苹果树的二氧化碳同化作用进行过许多测定,但是关于气候因子对苹果叶光合效率的影响方面的知识仍然稀少。而且不同来源的实验结果经常互相矛盾。例如某些研究者曾报导在光合率和太阳辐射之间在整个白天存在普遍的相关性,而另一些研究者则宣称光合率常常受到抑制。用于实验的叶片所处的实际情况很少测定过,周 Although dozens of researchers have conducted many measurements of carbon dioxide assimilation in apple trees over the past 45 years, there is still scarce knowledge about the impact of climatic factors on apple leaf photosynthetic efficiency. And experimental results from different sources often contradict each other. For example, some researchers have reported widespread correlations between photosynthesis and solar radiation throughout the day, while others claim that photosynthetic rates are often suppressed. The actual situation of the leaves used in the experiment is rarely measured, weeks